On real parameter stability margins and their computation

Abstract

A stability margin for linear control systems subject to real parameter variations can be computed from the constraints arising from the conventional Routh-Hurwitz criteria. The proposed stability margin is similar to the real-μ criterion, but with the bound on the real parameter variations given by a differentiable function. If the uncertain parameters are gaussian random variates, then an upper bound on the probability of instability is constructed. A computational procedure is proposed based on polynomial continuation.